Cholesterol levels in the American population
How are we doing? Cholesterol levels have fallen in recent years as statin usage has increased. A 2012 study published in the Journal of the American Medical Association. compared blood serum levels from 1994-1998 surveys to 2007-2010 surveys. Average cholesterol fell from 206 mg/dl to 196 mg/dl during that time. LDL fell and HDL (the cholesterol) increased. (Article: http://health.usnews.com/health-news/news/articles/2012/10/16/cholesterol-levels-dropping-in-us-adults-mostly-from-statin-use). The the National Center for Health Statistics and the federal Centers for Disease Control and Prevention studied about 100,000 patients and came up with this estimate of a 5% reduction in total cholesterol.
Congestive heart disease deaths and morbidity levels have fallen considerably (over 50%) since the 1980s, although this is due to many factors, not just cholesterol levels.
When statins were first released widely in the late 1980s and early 90s, they had a large impact. At this time statins were given mostly to high-risk patients - the “low hanging fruit’ who could benefit the most. Mortality from heart disease fell considerably in the final two decades of the 20th century - analysts who looked at the data concluded that about half of the decline could be attributed to medical intervention (including statins). The other half was due to changes in lifestyle that led to reductions in risk factors (e.g. patients lost weight, exercised more).
The Centers for Disease Control's survey of the American population found that between 2000 and 2006 the mean serum cholesterol level in men aged 40 to 59 declined from 214 mg/dL to 205 mg/dL. For men past age 60, the decline was from 206 mg/dL to 189 mg/dL, and for women over 60, the decline was from 224 mg/dL to 209 mg/dL.
The Centers for Disease Control report that 16% of American adults have high cholesterol (defined as over 240 mg/dL). This number already takes into account people who take statins to lower their cholesterol. The government's Healthy People 2010 program aimed to lower the percentage to 17%, so they account this as a success. However, it still shows that millions of people have high serum TC levels. The CDC also estimates that 8% of Americans have high cholesterol but don't know it.
How often are cholesterol levels checked? The medical establishment feels that if doctors are confident the patient is taking his or her medication, a check every 3 to 5 years is appropriate. Government statistics show that, most people do get at least the occasional screening. They report 65% of men and 70% of women (adults) have been screened in the past 5 years. Among seniors (over 60), the numbers are 91% for men and 88% for women. In the young adult cohort (ages 20 to 39), 52% of women and 41% of men were screened in the previous half decade.
Generally, men and women have about the same mean cholesterol levels, except in the senior (over age 60) cohort, where women on average have higher cholesterol levels than men. The higher levels in older women may be due to hormonal changes after menopause.
Letting our guard down
Could the health benefits of statins be too comforting? Could they entice patients to think they are now safe from heart problems and can ease up on lifestyle choices?
A study suggests that people who take statins may eat more than those who don’t. The statin patients had higher body mass index (BMI) than people who did not take statins. It is not clear why this is true or if there are problems with the analysis. But if it is true it could confirm what many health care practitioners fear: statins give people irrational assurance that they don’t have anything to worry about. Taking a statin: don’t worry about eating the big juicy steak! Another study found that men past age 65 were less active when they took a statin: Could this be because of muscle weakness, or, as many worry, because the statin patients figure the drugs have them covered and they can forgo exercise to stay heart healthy?
And here’s a more vexing problem: could the fact that real world results of statins – reduction in cardiovascular problems – don’t match projections based on clinical trials be partly due to this change in behavior? Could the benefits of statins be offset by a worse diet and less exercise and could those bad behaviors be why statins don’t produce the results they should? This is a flip side to the adherence problem – people who take their medications as instructed by then slough off on other ways to stay healthy.
This is a counterargument to the conspiracy ideas about Big Pharma foisting medicines that don’t work on us. If this is true, the drugs do work all other things being equal, but all other things are not equal.